This invention relates generally to a camera back for selective attachment to a front camera body and more particularly to a motorized camera back for use with self-developing type film units which may be advanced and processed from the camera back subsequent to their exposure from a front camera body releasably connected to the camera back.
Camera backs of the type having structure for both exposing and processing self-developing film units are well known in the art, and may be mounted on the back of a conventional camera utilizing complementary mounting structure and the exposure components of the camera. When thus mounted, as for example, in a manner of a standard film holder on a 4 by 5 press review camera, the camera back serves to slidably accept a photographic film unit so as to position a photosensitive surface at the focal plane of the camera for exposure. Furthermore, it will permit withdrawal or advancement of the film unit between compressive processing members to facilitate development of the exposed film by the diffusion transfer process. The demand for self-developing film for use in certain cameras is large enough that specialized accessory packs have been developed that are directly connectable to cameras having backs such as the Graflok back on the Speed Graphic camera.
One such patent for a camera back, as described in U.S. Pat. No. 3,505,943 by A. H. Bellows, issued Apr. 14, l970, discloses a motor driven pressure roll mechanism for use with camera backs of the above-described type where the principal components of a small DC electric drive motor are housed within one cylindrical pressure roll, the diameter of which is maintained at a minimum. Most recently, it has been proposed that such camera backs be utilized in conjunction with self-developing film units of the transparency type which require a sufficient imbibing time in a light tight environment subsequent to their advancement through a pair of pressure applying rollers.
Therefore, it is a primary object of this invention to provide a camera back of simple and economical construction for use with self-developing type film units.
It is also an object of this invention to provide a camera back for use with self-developing film units of the transparancy type wherein a light tight imbibing chamber is provided to receive the film units subsequent to their advancement through pressure applying means.
It is another object of this invention to provide a camera back for use with self-developing film units together with an adapter to accommodate connection of the camera back to a great many standard camera configurations less frequently, or only occasionally, used with self-developing type film.
It is an even further object of this invention to provide a motorized camera back for use with self-developing type film units where the motor is conveniently spaced in noninterfering relation with respect to the processing members together with an adapter for facilitating connection to the front camera body.
Other objects of the invention will in part be obvious and will in part appear hereinafter.